In simple words java 8 allows us to write code more precisely and concisely, which is better than writing verbose code in the java versions prior to java 8.

Example: Let’s sort a collection of cars based on their speed.

Java versions prior to java 8 :

Collections.sort(fleet, new Comparator() {
  @Override
  public int compare (Car c1, Car c2) { 
  return c1.getSpeed().compareTo(c2.getSpeed());
  }
}

Instead of writing a verbose code like above, using java 8 we can write the same code as:

Java 8 :

fleet.sort(Comparator.comparing(Car::getSpeed));

The above code is more concise and could be read as “sort fleet comparing Car’s speed”.

So why write a boilerplate code which is not related to the problem statement. Instead you can write concise code which is related to the problem statement and has SQL like readability.